I used to dictate only fairly infrequently on my phone, but since getting the Apple Watch I've started dictating a lot more. It started out with just a few brief efforts, usually made during times of desperation, but it proved to be robust enough that now I find myself doing it even when I could pull out my phone and type it. I feel that the dictation on the Watch rarely messes up and might actually be better than on the phone, but it's difficult to say whether that's true or whether it's just that I'm not able to scrutinize the Watch messages as closely and just don't see the errors.
Admittedly, it's frustrating to dictate a longer message and then have the thing mess up near the end, and not have a way to fix it.
Between using the pre-canned responses, emoticons, and dictation, I find that I do a fair amount of texting from the Watch. It's different from the iPhone, for sure, but if you already have the Watch, go on and give it a try. You might find that it works nicely and come to prefer it.